Patent GB-741119-A (GB)
Title: Apparatus for proportioning flows of different materials
Inventor: LOWE RUDY
IPC: G05D11/13
Filed: 1953-07-27
Abstract: 741,119. Proportionate mixing apparatus. PROPORTIONEERS, Inc. July 27, 1953, No. 20797/53. Class 86. [Also in Group XXIX] Apparatus for controlling the flows of two or more liquids or other flowable materials to be mixed in proportions which may be adjusted at will comprises for each flow line a differential gear 20, 20<SP>1</SP> one input shaft 27 of which is driven at a constant but adjustable speed from a master shaft 15 driven by a power unit, such as the electric motor 12, and the other input shaft 28 of which is driven by a rotary meter 33 in the supply line 42 of the component fluid, any difference in the speeds of the shafts 27, 28 causing movement of an output shaft 29 which is adapted, e.g. through an air control instrument 53 to control a valve 44 regulating the supply of the component fluid in such manner that the speeds of the input shafts are equalised and the flow of the component fluid is maintained substantially constant at its set value, means such as the valves 45, 45<SP>1</SP>, also being provided operative to recirculate liquid in all the flow lines without discharging it to the outlet if an incorrect flow occurs in any line. The speed of the shaft 15 is a measure of the delivery rate of the mixture of fluids and is adjustable by means of a variable speed transmission device 14 acting as a rate controller. The shaft 15 is connected to shafts 17, 17<SP>1</SP> &c. by level gearing 19, 19<SP>1</SP> and the shafts 17, 17<SP>1</SP> are connected to shafts 18, 18<SP>1</SP> by further variable speed transmission devices 16, 16<SP>1</SP> acting as ratio controllers to determine the percentage of each component of the mixture. The controllers 14, 16, 16<SP>1</SP> may be as described in U.S.A. Specification 2,405,957. The shafts 18, 18<SP>1</SP> are connected to counters 64, 64<SP>1</SP> through gearing 65, 65<SP>1</SP> and clutches 66, 66<SP>1</SP>. The shafts 18, 18<SP>1</SP> are connected to the input shafts 27, 27<SP>1</SP> through clutches 32, 32<SP>1</SP> and the flexible shafts 34, 34<SP>1</SP> from the meters are similarly connected to the input shafts 28, 28<SP>1</SP> through clutches 36, 361. Each pair of clutches 32, 36 and 32<SP>1</SP>, 36<SP>1</SP> is operated simultaneously by shafts 38, 38<SP>1</SP> operated by handles 105, 1051 projecting from panels 72, 72<SP>1</SP>, Fig. 1. The supply lines 42, 42<SP>1</SP> are fed by means of electrically driven pumps 43, 43<SP>1</SP> controlled by manually operated switches 61, 61<SP>1</SP>. A diaphragm-operated three-way valve 45 under the control of a spring-loaded solenoid-operated three-way pilot valve 46 is interposed in the line 42 and operates on failure of the appropriate liquid supply or on failure of the pressure in an air line 48 supplying the instrument 53 and the pilot valve 46 to divert fluid through a branch pipe 47 back to the pump 43 for recirculation and cut off the portion 60 leading to the mixing manifold. The valve 46 is controlled by high and low speed limit switches 57, 58 operated by an arm 59 on the output shaft 29 of the differential gear 20. Indicator lights 62, 63 show which switch is closed. A valve 109 in the supply line 54 from the air line 48 to the instrument 53 is opened when the clutches 32, 36 are engaged by a lever 112, Fig. 7, connected to the shaft 38. The output line 55 from the instrument 53 leads to the actuating diaphragm of the valve 44. The clutches 66, 66<SP>1</SP> are engaged to bring the counters 64, 64<SP>1</SP> into operation by the rotation of a shaft 67 by a plunger 119 in an air cylinder 68 supplied through a three-way solenoid actuated valve 69 itself supplied from the line 48. Each liquid supply line has an air eliminator 50 containing a float to seal off a vent when the system is full and a solenoid-operated three-way valve 51 which in one position allows air into the highest point of the recirculation system to blow back any residual liquid prior to the institution of a fresh blend. The electric circuit is controlled from a master switch 120 having five positions corresponding to "OFF", "DRIVE", "TEST", "BLEND", and "BACK FLOW". In the DRIVE position the motor 12 and the shafts 15, 18, 18<SP>1</SP> are started up and the left-hand indicator light 123 lights up. The pumps 43, 43<SP>1</SP> are then started up by the switches 61, 61<SP>1</SP> and the controllers 14, 16, 16<SP>1</SP>, are set. The clutches 32, 36, are engaged and the instrument 53 rendered operative by the handle 105. The counters 64, 64<SP>1</SP> are next set to zero. The switch 120 is then moved to the TEST position in which the valve 69 is operative to cause the clutches 66, 66<SP>1</SP> to be engaged so that the counters 64, 64<SP>1</SP> become effective. The middle light 123 is illuminated in the TEST position. The counters 64, 64<SP>1</SP> are automatically de-clutched at the end of a test run the duration of which is set by a timer 122. After being checked the counters 64, 64<SP>1</SP> are returned to zero and the switch 120 is moved into the "BLEND" position in which the right-hand light 123 is illuminated. In this position the valves 45, 45<SP>1</SP> close the branches 47, 47<SP>1</SP> and open the portions 60, 60<SP>1</SP> of pipes 42, 421. At the same time, the counters 64, 64<SP>1</SP> are again clutched in and the apparatus completes its run unless interrupted by operation of the limit switches 57, 58 in which case the recirculation branches are immediately re-opened and the counters 64, 64<SP>1</SP> are declutched. This state of affairs continues until the deflect which caused the switch 57 or 58 to be closed is put right. The apparatus then proceeds again on blend makes good any deficiency as shown by the instrument pointers 125, 125<SP>1</SP>. In the "BACK FLOW" position, the pumps 43, 43<SP>1</SP> are stopped and the valves 51, 51<SP>1</SP> opened to admit compressed air to the recirculation systems 42, 47, and 42<SP>1</SP>, 47<SP>1</SP> and drive any residual fluid back to its respective source. On returning to the "ON" or "DRIVE" position, lights 124, 124<SP>1</SP> indicate that each system is filled with liquid again.